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5 votes
1 answer
355 views

How do you traverse a rectangular grid of points while turning as little as possible?

Suppose I have a lattice grid of $m \times n$ points in the plane, with $m\leq n$. I want to traverse this grid in such a way as to minimize the total amount of turning that occurs. I am pretty sure ...
Tom Solberg's user avatar
  • 4,049
1 vote
0 answers
93 views

Traveling Salesman: Optimization over cities, not distance

In the classical traveling salesman problem, we are given a graph of cities with distances between each city and are asked to find the shortest path that traverses all of the cities. Meaning that the ...
MathManiac5772's user avatar
1 vote
0 answers
35 views

How to chose the start vector for the MTZ variables

In the context of LP-formulations for the Traveling Salesman Problem the MTZ constraints prevent subtours via $n$ (i.e. effectively $n-1$) additional variables $$u_1=1\\2\le u_2,\,\dots ,\,u_n\le n\\ ...
Manfred Weis's user avatar
  • 13.2k
0 votes
1 answer
54 views

Relation of 1-trees to optimal tours

Question: given a complete symmetric graph $G(V,E)$ with $n$ vertices and edges $e_{ij}$ having weight $\omega_{ij}$, does there always exists a vector of vertex potentials $(\pi_1,\,\dots,\,\pi_n)$ ...
Manfred Weis's user avatar
  • 13.2k
3 votes
2 answers
1k views

Is there a lower bound for the computational complexity of the traveling salesman problem?

A (non-mathematician) acquaintance of mine recently proposed to me a polynomial-time algorithm for solving the traveling salesman problem. While I was able to point out a flaw in his approach, it did ...
Simon Rose's user avatar
  • 6,290